Perovskite–organic tandem solar cells

The bandgap tunability of halide perovskites makes perovskite solar cells excellent building blocks for multijunction architectures that can overcome the fundamental efficiency limits of single-junction devices. Meanwhile, the introduction of non-fullerene acceptors has led to tremendous advances in the field of organic solar cells. Organic and perovskite semiconductors share similar processing technologies, making them attractive partners for multijunction architectures. This Perspective article outlines the prospects and challenges of perovskite–organic tandem solar cells by highlighting the key aspects of the individual building blocks and how they interact with one another. The discussion includes the role of non-fullerene acceptors in narrow-gap organic solar cells with high operational stability, the need for long-term stability in wide-gap perovskite solar cells and the impact of the design and functionality of high-quality interconnects on the characteristics of the tandem device. Finally, the prospects of perovskite–organic tandem solar cells are benchmarked against other emerging tandem solar cell technologies.